25 replies to this topic

[don.siegel]

I'm sort of vaguely getting ready for the next padlock drag race, and somewhere in the back of my mind I remembered I had two incomplete Russkit dragster chassis that I thought I could combine into a complete one... well, that was my memory in any case! 

 

Turns out one had the front rails shortened, and the full-length one had been lightened all the way, so I'm still short a complete Russkit chassis (apart one still in its blister...), but these will still do for runners. But I especially noted a couple odd facts on the two motors involved... 

 

 

One seemed to be a pretty stock DC85 and the other one was a hotted up version, lightened and epoxied. But when I looked closer at the stock one, I noted something funny...

 

 

Yep, the guy had threaded the motor shaft and was using two 5-40 nuts to hold on the pinion! Pretty strange, eh? Unless he had previously threaded it for direct drive, and then gave up on that and cut off one shaft...

 

The other one looked well epoxied, but it wouldn't work... I later put those axle spacers in there, but the original motor didn't have any spacers to take up the space where he had cut the lams, one bushing was put in the wrong way, and the whole thing was binding... once I put it together like this, it wound up very well, definitely faster than the stock model. (and still needs to be reassembled correctly). 

 

 

But instead of doing all that, I also took out a brand-new DC84-6, and am thinking of using that... Not sure how the 84-6 really differs from the 85-6... lams are the same, maybe in the winding. 

 

 

What some guys do to motors... 

 

Don 

[gluebomb]

Some nice bits; is it possible the threaded shaft on that arm is factory and from something else ? 

And while we're talking Pittmans; was there ever any alternative brush tensioning used for these, ie something better than the phenolic plate and spring combo ? I'm guessing a flat coil spring like those used on the 36D simco kits and similar might work but have you seen this done ever ?

That last proxy looked like a lot of fun, may have to join in on this one...

[SlotStox#53]

Don you brave soul venturing into the Padlock Zone Good to see you're starting early !!

Certainly never seen that threaded shaft before! Most intriguing.

Gluebomb, I think I've seen the Simco type spring used on a dc65x before & have thought about using one on the bigger cousin. Certainly can't be any worse than the existing arrangement !

[gluebomb]

 Certainly can't be any worse than the existing arrangement !

 

Yes, i agree, am no fan of that set-up at all, have spent far too long on hands and knees looking for the various bits after they launch themselves...

I'll look through some of the old mags and see what i can find...

[don.siegel]

Thanks for replies guys. 

 

I've never seen a flat coil spring used on these motors; some of the inline ones have separate springs, but all the big ones seem to use this plunger setup. It doesn't bother me, but maybe I like crawling around on my knees, looking for springs! 

 

That's definitely the original arm with the threaded part; only Wilson as far as I know made a motor with the threaded shafts on both sides, for direct drive, and I'm pretty sure it wasn't the same arm size, tho guess I should check before I say that! 

 

Don 

[SlotStox#53]

but maybe I like crawling around on my knees, looking for springs! 
 
Don 

Have done that very thing looking for that plunger very recently

Look forward to seeing what you make of these Russkit padlock warriors

[Champion 507]

Don,

 

My 2 remaining brain cells moved just a little (not much) when I saw the pic of the threaded Pittman arm shaft. Seems like I remember reading something about that way back in the dark ages in one of the slot/model car mags of the day. But that was over 40 years ago, so who knows?

 

Maybe the Pittman guy from Colorado that Steve Okeefe got to help him with the Pittman section of theindependentscratchbuilder can shed some light on it.

 

As someone once said:

 

[Pitt Man]

Hi guys, Pittman guy from Colorado here

 

Hey Don, cool motors you have there!

 

The DC84 has two less laminations making the motor about 1/16" narrower than the DC85. A little more speed and a touch less torque than the DC85. A bit off topic, the relatively unknown DC86 is also a cool padlock, it has a couple more laminations than the DC85, once again, more torque, less speed. Unfortunatly I've only found these motors in 12 volt versions. A six volt would be just awesome for drags. All three of these motors share the same lams, brushes and frame castings, just a different lam count and armature stack lengths.

 

As far as the threaded armature shaft....I've never seen this on a Pittman before. I like Don's idea of a failed direct drive attempt. Then again, I've been embarassed before saying "Pittman never made that!"

 

I also have never seen an alternate brush spring set up for the DC85 other than the Ram hop-up spring and plunger set. (3 springs, soft, med., hard) I find the single plunger is MUCH easier to handle than the DC65's tiny pitchforks that love to hide in the carpet.

 

I'm looking forward to the new rash of padlock dragsters being built! I'm currently working on one myself for next year's drags. Get'em goin' guys.

[SlotStox#53]

Hi Pitt man

Thanks for the great information! Never heard of that dc86 before, what's the standard number of lams for the dc85?

Padlock Dragsters rock

[don.siegel]

Amen, thanks Bob, 

 

If I remember right, I counted 13 on the DC85; thought it was the same on the 84, but obviously I didn't count too closely! 

 

I have a DC86 as well, but it's kind of hefty for a dragster - not as heavy as the 9003 boat motor, but still big! 

 

Don 

[boxerdog]

I kinda like the spring and plunger arrangement.

 

I am sure that sometime in the future I will find the 5 or 6 that I have fired into orbit in my basement workshop. I guess the fingers aren't as nimble as they were 50 years ago.

 

And the pitchforks are much worse (read smaller) plus they get soggy and bow sometimes.

[Foamy]

Squeeze plungers together and use a small hemostat to clamp.

Threaded shaft motor for a model boat?

[don.siegel]

Here's what I've put together so far; the Russkit went together pretty well, and I used a different hole for the drop arm, since the original was gone, from the lightening slots! It's a bit loose, so will have to fit some bushings if and when I actually run this dragster. 

 

I did finally choose the epoxied motor, and took it apart and tried to fit it together a bit better.... boy, these laminated motors are tough to work on! As soon as you take out the screws, all the lams dive towards the arm, but not like synchronized swimmers! I'm beginning to understand better why the Can took over.... I'm not totally satisfied with this yet, but I wanted to get it put together and see what it looked like. 

 

I kept the arm in the magnetic field, so hopefully I won't have to rezap this, altho I'm sure a little animal magnetism would help it on the strip... 

 

Funny how, no matter how straightforward you think something is going to be, it always winds up more complicated! 

 

Don 

 

 

 

[Gator Bob]

 

The DC84 has two less laminations making the motor about 1/16" narrower than the DC85.

 

With your help I was able to score that mint DC84-6 .. nice  Thanks!

 

As far as the threaded armature shaft....I've never seen this on a Pittman before. I like Don's idea of a failed direct drive attempt. Then again, I've been embarassed before saying "Pittman never made that!"

 

That is what I thought too....

 

I also have never seen an alternate brush spring set up for the DC85 other than the Ram hop-up spring and plunger set. (3 springs, soft, med., hard) I find the single plunger is MUCH easier to handle than the DC65's tiny pitchforks   that love to hide in the carpet.

 

I'm looking forward to the new rash of padlock dragsters being built! I'm currently working on one myself for next year's drags. Get'em goin' guys.

 

 

 boing-oing-oing  

 

 

And the pitchforks .....  are much worse (read smaller) plus they get soggy and bow sometimes.

 

 

 

Threaded shaft motor for a model boat?

 

This could be it.... The motor I got from Paul Bass is threaded. The threads are rounded (not pointy) as it looks like it would be for a spring flex drive shaft.

Maybe/Maybe not

 

Here's what I've put together so far; the Russkit went together pretty well,

 

"I Like It"

[SlotStox#53]

Very nice Don ! Looks about ready to rock

Feel your pain stripping those padlocks down , the laminations can get a little frustrating

You should be fine with magnet keeping the arm in , although a recharge after decades wouldn't hurt, but you wouldn't of lost any .

[hiline2]

About keeping the arm in to maintain a magnetic field, the instructions that come with a RAM 6v arm say to place a steel washer across the lamination opening  before removing the arm to also maintain the magnetic field, 

 

Any  pics explaining the simco spring set up ?

[gluebomb]

 

 

Any  pics explaining the simco spring set up ?

 

Hey Paul,

You can see the Simco type spring on a 36D can in this thread:

 

http://slotblog.net/...6d-anglewinder/

 

Easily fabricated and I think it would work for a pittman 85 - worth trying anyway ?

[don.siegel]

I might need to try that on mine! Just noticed that the two screw heads are actually touching the brush arms, so that's a definite short circuit! Of course, first I'll try flatter heads, but may need to go the Simco route... 

 

Also found some articles by Bob Braverman in Rod & Custom on this chassis (his own design) and the DC85 he modified for it... the motor looks very much like this one in fact. Will scan those articles today or tomorrow... 

 

Don 

[hiline2]

Gluebomb ! Wow great idea, where does one find those or you thinking "making" the sptings ?

[gluebomb]

Hey Paul,

 

I've bent those up for can motors with music wire but never for the bigger Pittmans - doubt i'd the first to try it though ? Pretty easy once you figure out the radius you need but not sure if there's any advantage in terms of performance.

I've a big old 85 just sitting, will play around and post back if I can get it to work.

 

 

Has anyone had any luck with the bigger Kemtron units, the Mustang or Bronco with the 1/8 shaft ? I've got a 8v Mustang and it looks a step up from the X503 in terms of consruction but i've never run it in anything - do they go good ?

[hiline2]

The only downside to the Kemtrons ( Ive heard) is the brush arrangement is weaker design then Pittmans or Rams. I've got a bevy of Mustangs and broncos to play with too ! 

[gluebomb]

Hey Paul,

Pretty sure there's a thread somewhere about upgrading the Kemtron bush springs with something stiffer but not sure where i saw it ? I guess you could maybe adapt a pittman type brush assembly to fit though - that with the simco style spring might be a good little set up to play with...

For me the weak point has always been the pressed brass mounts on the X503 - if you look at those wrong the whole motor tends to bind so the cast bit on one side of the Mustang is a nice touch, the epoxied windings and that fat com are pretty impressive looking also.

Nice to see people digging into these motors again and the recent proxy cars were all really cool builds; stuff pre-dates me by a fair bit but it's by far my favorite era of bits to mess around with...

[proptop]

I got a Pittman 85 in a box lot of stuff...

It has a baby diaper "safety pin" brush spring (pre "Pampers" days, huh!?  )

The guy cut it in half (approx) and bent the ends of the wires to better suit the brushes...

 

I thought it was kinda neat...improv...  and seems to work well...

[hiline2]

very innovative ! 

[don.siegel]

Thanks Bob! 

 

A little after the fact, but here are Bob Braverman's articles on hopping up a DC85A and his own design Russkit dragster, from Rod & Custom, April and May 1964 (so this is really 1963 technology). Looks like this was the inspiration for the motor I use in this Russkit rail, but he forgot the extra nuts, and didn't balance the arm. The Kemtron X503 hopup article was in the February 65 issue...

 

First... 

 

 

[/URL]

Now we move to the next month's issue, and Bob's own article on building the dragster he designed, which was sold by Russkit. Note that the one in the article seems to be a prototype, without the holes in the production model. And not only is it on the cover...

 

 

... it's also on the back page. And that's how magazine advertising works! 

 

 

Here's the article itself. 

 

 

 

 

Don